Selector switch drive



June 6, 1950 G. DEAKlN ETAL SELECTOR SWITCH DRIVE Filed June 25, 1948 Ra 3 m NM INVETORS. GERALD DEAKIN &

JOHN C. JABLONOWS Kl A TTORA/fY- Patented June 6, 1950 SELECTOR SWITCHDRIVE Gerald Deakin, New York, N. Y., and John C. Jablonowski, JerseyCity, N. J., assignors to International Standard Electric Corporation,New York, N. Y., a corporation of Delaware Application June 25, 1948,Serial No. 35,203

Claims.

This invention relates to new and useful improvements in catch mechanismfor a combination drive and clutch which may be used to move the brushcarriage of one or more selectors of an automatic telephone system.

In an application by Gerald Deakin, Serial No. 35,202, filed of evendate, certain features of the catch mechanism which is the subject ofthis invention are disclosed but not claimed.

The brush carriage of a selector is mounted on a movable rack having twoparallel toothed surfaces each of which is permanently engaged bydriving pinions which drive the rack back and forth. In order to imparta reciprocating movement to the brush carriage a clutch mechanismalternately couples and de-couples constantly rotating arms to gears,each of which is permanently in mesh with a pinion. Each arm has a pinby means of which it engages a. catch fastened to a gear. One arm drivesthe brush carriage from right to left and is disengaged from itscooperating catch by disengaging means, whereupon the other arm engagesits catch and drives the carriage from left to right, this cycle beingcontinuously repeated.

According to the present invention pin retaining means are provided ateither end of each catch to prevent disengagement between a pin and acatch except by the disengaging means. The pin retaining means comprisea notch at one end of a catch for seating a pin While an arm is drivinga gear and a hook at the other end of the catch for preventing the pinbeing disengaged from the catch if the catch should be accidentallymoved in a direction opposite to the movement of the pin. Thepossibility of such accidental movement is particularly present duringthe shifting of the travel of the brush carriage from right to left orvice versa.

The features of the present invention will be disclosed in the followingdescription in which the details of the drive and clutch, as well as thecatch mechanism, will be explained so that the operation of the catchwill be better understood.

In the drawings:

Fig. 1 is a top plan view;

Fig. 2 is a section along the lines 2-2 of Fig. 1; and

Fig. 2a is a plan view of a catch.

In the following description it is assumed that a main driving shaft(not shown) is to the left of the selector. If the shaft is to the rightthe selector parts are turned upside down and operate in the samemanner.

A rack I carries near one end, a brush carriage generally indicated at 2provided with the usual brushes which cooperate with a terminal bank andfeeder strips of a selector. The rack has a central slot 3 separatingtwo parallel toothed driving edges 4, 5 which when engaged by pinions.about to be described, drive the rack back and forth in a, horizontalplane. A guide piece 6 held by screws 1 in slot 3 has grooves on twosides through which the smooth edges of rack I may slide.

Toothed edge 4 of rack I is permanently in mesh with a driver or pinion8 and toothed edge 5 is permanently in mesh with a driver or pinion 9.Eachpinion is free to rotate on pins Ii] mounted on brackets II held tobase plate I2 by screws I3. Locking rings I4 hold the pinions on pinsl0.

As best seen in Fig. 2 pinion 9 is permanently in mesh with a gear I5and pinion 8 permanently in mesh with a similar gear I5. Gears I5 and I6are situated one above the other to rotate freely on bushings I1, I8surrounding a driving shaft I9 which is driven in the directionindicated by the arrow by a flexible driving gear 20. The operation ofdriving gear 20 is well known in the so-called rotary power drivenselectors and will not be herein described.

When gear I5 is coupled to driving shaft l9 by the clutch mechanismabout to be described, it will drive pinion 9 which in turn drivesthrough toothed edge 5, rack I and brush carriage 2 mounted thereon fromright to left. During this movement pinion 8 which is in mesh with edge4 rotates freely about its pin It! and drives gear It freely about shaftI9. After brush carriage 2 has been driven to the left terminal positionof rack I, the clutch mechanism de-couples shaft I9 from gear I5 andcouples gear It to the shaft which drives by means of pinion 8 and edge4, the rack back from left to right. Pinion 9 and gear I5 now rotatefreely. At the completion of the left to right travel of the brushcarriage the right to left movement is once again commenced as abovedescribed.

Shaft I9- rotates in a bushing 23 projecting from a hole in bottom plateI2. Two driving arms 24 and 25 are keyed to shaft I9 by its fiat sideindicated at 26. Driving arm 24 is above gear I5 and driving arm 25below gear IS. The two driving arms and the gears are held in place onshaft I9 by means of nut 2'! forcing the assembly on to I5 facingdriving arm 24 and a catch 3| is fastened to the surface of gear ii;facing driving arm 25. These catches are displaced approximately 30 withrespect to one another so that there will be no lost motion between thecoupling of one gear and the de-coupling of the other gear as movementof the rack is shifted from right to left or vice versa.

Fingers 32, 33 are respectively pivoted at 34, 35 to arms 24, 25. Leafsprings 36, 31 are attached by screws 38 respectively to arms 24, 25.Ends 33 of the springs rest on projections '40 of the fingers and tendto rotate each finger about its pivot in a clockwise direction. Thismotion is limited by stops ll forming part of .the driving arms. Nearthe free end of fingers 32, 33 ,-pins 42, 43 project and are adapted toengage respectively catches 30, 3|.

As shown in Fig. 1, pin 42 is engaging rear notch 48 (shown for catch 3l) of catch 30. Since finger 32 rotates with arm 24 and shaft [9, gear Iwill'also be rotated. Gear [5 in turn drives the rack'through thepinion'iland edge 5. When gear l5 has completed one rotation carriage '2will have been driven all the way across the selector and portion Zi'iof the finger will contact top roller 45 ofengaging lug i''projectingfrom base ["2 to which it is secured by nut'ZB. Lug 4'5 pushes 'finger32ina counterclockwise direction as'it cofnesby, lifting pin '42 out ofnotch 49in catchSfi thereby de-couplingdrivingarm 24 from gear 15. I

While gear 95 is being driven by arm '24, finger 33 is also rotated withshaft is andgear T6 is rotated in-a counterclockwise direction by pinion8. Catch-3i of gear 16 will hot be engaged by pin 4'3 untilportio'n'fiti of finger 33 engages roller 5! of lug 46 which rotates thefinger sufficiently'for pin '43 to engage end l lof catch 3! and ridealong edge E8 of the catchand nestle into notch 49. As finger 32 isbeing de-coupled by lug 46 from catch 3!! and gear I G, pin c3 lodgesinnotch 49 of catch 3| and finger 33 commences to drive gear H in aclockwise direction and the brush carriage'from left to right.

From Fig. 2a it is-seen that catch 3| has retaining means for pin 43 ateither end consisting of notch A9 and hooked end 4?. Notch 49 isfo'rmedso that when pin 43 lodges in it, one side of the pin rests against thebottom of an overhangingl'ip Ell and the other-.side against arelatively sharply inclined wall 6|. In this way pin "43 is held againstlateral displacement and since there is no lost motion between thedriving and driven parts, overstepping by the selector during hunting iseliminated.

.Hooked end "4"! of catch 3'! prevents unwanted disengagement of theparts and possible breakage between the driving and driven parts. Suchdisengagement could, for example, be brought about, in the absence ofend 41, if one were to move by hand the brush carriage during the periodof changeover from right to left or left to right movement of .thecarriage after one of the driving pins. e..g. '42,'h'ad been lifted outof match 45i-of'catch'30 andthe other pin, e. g.'43, had not yet lodgedini1ot'ch49 of catch 3!. However, wall 5 3 of end '4"! would arrest anymovement of a driving pin brought about by moving the carriage by hand.A driving pin, therefore, will always beelfe'ctively connected toits'catchuntil lifted out by lug 39.

The alignment of gears I5, "I 6 so'that catches 3 l will be in properrelationship is accomplished-byfirst alignih'g two holes 54' in gear I5with two holes 55 (only one of which is shown) in gear 55, and thenrotating the top gear back one hole. The pinions may then be droppedinto position and the operating fingers latched to the gears. Naturallysince gears l5, [6 are moving in opposite directions holes 54, 55 willbe in alignment-'only'i'n one position of the gears. This is not theposition shown in Fig. 1.

It will be clear from the foregoing that because of the accurate andclose fit between the respective parts of the assembly back lash iseliminatedand overstepping by the selector even when hunting at highspeeds is virtually impossible.

What is claimed is: 1. In a drive for a reciprocating carriage, a

driving shaft, means for driving the carriage in alternate directions, apin rotatable with said driving shaft, and a catch movable with saiddriving means and in cooperative relation withsaid and having pinretaining means preventing disengagement of'th'ep'i'n fromthe catch.

25A drive for a reciprocating carriage, comprising a driving shaft,means mounted on said driving shaft for driving the "carriage inalternate directionsftwo pins rotated with 'sa'idmeans, two catches, onemovable with the means for driving the carriagein one directioniand' theother with the ineansifor'driving the carriag'e'inthe oppositedirection, meansformov'ing one'pin into engagementwith one catch and'theother pin out of engagement with the other catch and vice versa, and twoLpin retaining means on each catch preventing removal of a pin from acatch by rotation in 'eith'erdirection when a pin is 'en gaged to acatch.

3. The device according to claim 2, and in which said pin retainingmeans comprise 'a hook atone endof a catch and a notch at the other end.

'4. The device according to claim 2, and in which said pin retainingmeans comprise a hook at one end of a catch having'a pin arresting walland a notch at the other end of the catch having an overhanging lip.

'5. In a "drive for a selector brush carriage a driving shaft, arack'carrying the brush carriage and having two toothed edges,cooperating pinion for each edge in permanent mesh therewith, twodriving fastened to the shaft, two operating fingers mounted on thearms, .a pin projecting from each of said fingers, two gears freelyrotatable around the shaft, each of said gears in permanent mesh withone of said pinions, a catch on each of said gears cooperating with thepin on each of said fingers, a hook at one end of said catches and anotch atthe other end of said catches, "lug means for alternatelyconnecting and disconnecting apin to a catch as the driving shaftrotates, whereby a finger remains connected at alltimes to a catch untilreleased therefrom by saidlugmeans.

GERAIQDE'AKIN. JOHN C. JABLONOWSKI.

REFERENCES crest The following references are of record iii-the file ofthis patent:

UNITED PATENTS Number Name "Date X71688 Bates July 27,1833 331,524'Metzger et al. Dec. 1, 1883 1,864,499 Grigsby "June 21,1932

